Regimented placement of self-assembled Ge dots on selectively grown Si mesas

The control of positioning of self-assembled dots is critical for the fabrication of regimented arrays in signal processing applications. We report the controllable positioning of self-assembled Ge dots using selectively grown Si mesas as a template. The dependence of the dot arrangement on growth temperature and Ge thickness has been investigated. The experimental results show ability to control the positioning of Ge dots based on energetically preferential nucleation. The Ge dot growth on Si mesas is demonstrated to be a promising way to realize the placement of regimented arrays of self-assembled dots and even a single dot. This technique can be extended to other heterostructure growths.